Have you ever played with a flashlight and a magnifying glass? Were you able to focus the rays to a single point?

source: simplescience.info

Magnifying glass is a useful tool and contains a single optical lens. Borrow some magnifying glass and figure out its focal length. Can you build a gentle LEGO mechanics with a light source and a light sensor that will automatically measurethe focal length of an inserted magnifying glass? Try to use your device with various magnifying glasses or optical lanses.

When did you last time visit a theater? One of the interesting occupations in the theater has the illuminator (lighting manager). His or her job is to turn on and off the lights, set them up, and point the reflectors so that they illuminate the scene on the stage correctly and thus improve the artistic quality of the performance, focus the spectator's attention to important elements of the story on the stage.

source: sru.edu

Task: Build and program an illumination system for a theater stage. The stage has a rectangular shape and its borders are marked. A solo actor moves around the stage, you can use a hand for this. The system uses LEGO-sensors to detect the actor's motion and controls the direction of the illuminating light source, for instance a flashlight with a narrow light cone. The light is mounted on a stand. The oucome of the control actions of the system is that the illuminating light is always focused on the actor.